Priority is claimed with respect to Application No. 199 43 320.8 filed in the German Patent Office on Sep. 10, 1999, the disclosure of which is incorporated herein by reference.
The invention relates to an arrangement for reducing the noise level of tobacco-processing production machines, particularly in an operator region of a production line comprising at least two production machines disposed at an angle to one another.
Production machines of the tobacco-processing industry primarily encompass cigarette-production machines and filter-attachment machines, which are preferably joined diagonally at a 90xc2x0 angle to form a production line. The machines may further include packaging machines and other standard tobacco-industry components, such as filter-production machines and article-transport devices, the latter representing a secondary source of noise. Particularly in the aforementioned production line, an operator, who is preferably positioned in the corner zone between two machines, is exposed to a great deal of machine noise. Previous efforts to reduce the noise have been unsuccessful in preventing operating noises created by mechanical components, and flow noises produced by process air, especially suction noises, from being emitted from the machines and entering the operator region, because it is not possible to hermetically seal the machine.
It is an object of the invention to implement further, more effective anti-noise measures.
In accordance with the invention, this object is accomplished in that the reflection surfaces facing the operator region are provided with sound-damping material.
According to a modification, a particularly effective noise absorption is attained when the sound-damping structure of the damping material faces the operator region. This is realized particularly simply if the reflection surfaces formed by the cladding of the production machines are equipped with damping mats.
An embodiment that is especially easy to handle, exchange and adapt involves a configuration of damping mats as exchangeable damping elements having a neutral shape.
The damping elements are advantageously embodied as truncated cones that are connected to the machine cladding by a central screw connection.
In an advantageous embodiment, in which the absorption properties are guaranteed, and, at the same time, an attractive appearance is assured, the absorption surfaces of the truncated cones are covered with cladding sheets having openings in the manner of a sieve.
In a preferred embodiment of the absorption surfaces as parts of a removable carriage, the damping mats are inserted between inside reflection plates and outside, sieve-like cladding surfaces, with the reflection plates and cladding sheets additionally being inserted into corner-profile strips whose hollow space is filled with damping material. This achieves a machine cladding that has a smooth surface and effective absorption properties.
In the sense of a unified, sound-absorbing machine cladding, it is also provided that, in an absorption surface embodied as a door, inside and outside cladding sheets are inserted, with an interposed reflection surface and hollow spaces filled with damping mats, into a profile frame embodied as a hollow body and closed by corner connectors, the frame being provided with a pivoting axis and recessed sealing elements. To increase the stability of such an arrangement, it is also proposed that the cladding sheets and the reflection surface be stabilized by means of spacing sleeves that are screwed together.
The versatility of the construction principle exhibited by the cited arrangements is expanded in a modification in which two viewing panes are inserted into a profile strip in an absorption surface embodied as a window flap, with the strip and an inserted cladding sheet limiting a hollow space filled with damping mats.
For the anti-noise measures to include a relatively large base surface that reflects the machine noises, it is further proposed for at least one standing region for the operating personnel, which borders the production line of the machines, be provided with a damping layer. This type of arrangement can be embodied to be particularly effective and easy to handle if, in accordance with a modification, the damping layer comprises damping tiles laid under the entire surface of the production machines.
This type of arrangement becomes especially stable and effective in terms of damping if the damping tiles are embodied as tile boxes filled with damping material and disposed in the manner of a grid between supports. The boxes are easily accessible, without losing their absorption properties, because they are provided with a gridiron support that forms a standing surface.
With the arrangement under the entire surface of the machines, a high contact stability must be present beneath the machine feet, which is achieved by the insertion of damping tiles having stress-specific layers into the gridiron support.
To facilitate the sweeping of these gridiron supports, and to prevent tobacco fibers from entering the damping material through the grid openings, a preferred modification provides that a tile box forming a floor tile has a gridiron that includes elevations, as well as lateral and base-side buffers, which avoids a direct contact between adjacent tile boxes, and between tile boxes and the floor, that would effect a solid-borne sound transmission.
The penetration of tobacco fibers or other undesired elements, or moisture, into the damping materials is prevented by a preferred embodiment, in which the gridiron support of a tile box has rounded edges and is positioned on a sound-permeable film, which covers a fine-mesh sieve lying on the damping mat.
To complete the anti-noise measures, it is further provided that the air-flow cross sections required for the process air supply of the production machines are predominantly concentrated in flow conduits clad with sound-damping material.
In connection with the damping mats covering the floor, a further proposal allows flow-related noise sources to be controlled by the concentration of sound-damped flow conduits in the floor region of the production machines.
The flow noises are additionally reduced by the embodiment of air-passage gaps of the machine cladding as sound-absorbing damping gaps.
The advantage attained with the invention is that, regardless of specific, particularly sound-intensive, noise sources inside the machines and the more or less successful isolation of the noises from the outer operator region of the machines, the entire sound spectrum is generally reduced, because the operating noises emitted by the machines, which have different frequencies, are absorbed outside of the machine interiors, and are therefore considerably reduced with respect to the operating personnel.